/*-------------------------------------------------------------------------
 *
 * brin_validate.c
 *      Opclass validator for BRIN.
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *      src/backend/access/brin/brin_validate.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/amvalidate.h"
#include "access/brin_internal.h"
#include "access/htup_details.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/syscache.h"
#include "utils/regproc.h"


/*
 * Validator for a BRIN opclass.
 *
 * Some of the checks done here cover the whole opfamily, and therefore are
 * redundant when checking each opclass in a family.  But they don't run long
 * enough to be much of a problem, so we accept the duplication rather than
 * complicate the amvalidate API.
 */
bool
brinvalidate(Oid opclassoid)
{// #lizard forgives
    bool        result = true;
    HeapTuple    classtup;
    Form_pg_opclass classform;
    Oid            opfamilyoid;
    Oid            opcintype;
    char       *opclassname;
    HeapTuple    familytup;
    Form_pg_opfamily familyform;
    char       *opfamilyname;
    CatCList   *proclist,
               *oprlist;
    uint64        allfuncs = 0;
    uint64        allops = 0;
    List       *grouplist;
    OpFamilyOpFuncGroup *opclassgroup;
    int            i;
    ListCell   *lc;

    /* Fetch opclass information */
    classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
    if (!HeapTupleIsValid(classtup))
        elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
    classform = (Form_pg_opclass) GETSTRUCT(classtup);

    opfamilyoid = classform->opcfamily;
    opcintype = classform->opcintype;
    opclassname = NameStr(classform->opcname);

    /* Fetch opfamily information */
    familytup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfamilyoid));
    if (!HeapTupleIsValid(familytup))
        elog(ERROR, "cache lookup failed for operator family %u", opfamilyoid);
    familyform = (Form_pg_opfamily) GETSTRUCT(familytup);

    opfamilyname = NameStr(familyform->opfname);

    /* Fetch all operators and support functions of the opfamily */
    oprlist = SearchSysCacheList1(AMOPSTRATEGY, ObjectIdGetDatum(opfamilyoid));
    proclist = SearchSysCacheList1(AMPROCNUM, ObjectIdGetDatum(opfamilyoid));

    /* Check individual support functions */
    for (i = 0; i < proclist->n_members; i++)
    {
        HeapTuple    proctup = &proclist->members[i]->tuple;
        Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
        bool        ok;

        /* Check procedure numbers and function signatures */
        switch (procform->amprocnum)
        {
            case BRIN_PROCNUM_OPCINFO:
                ok = check_amproc_signature(procform->amproc, INTERNALOID, true,
                                            1, 1, INTERNALOID);
                break;
            case BRIN_PROCNUM_ADDVALUE:
                ok = check_amproc_signature(procform->amproc, BOOLOID, true,
                                            4, 4, INTERNALOID, INTERNALOID,
                                            INTERNALOID, INTERNALOID);
                break;
            case BRIN_PROCNUM_CONSISTENT:
                ok = check_amproc_signature(procform->amproc, BOOLOID, true,
                                            3, 3, INTERNALOID, INTERNALOID,
                                            INTERNALOID);
                break;
            case BRIN_PROCNUM_UNION:
                ok = check_amproc_signature(procform->amproc, BOOLOID, true,
                                            3, 3, INTERNALOID, INTERNALOID,
                                            INTERNALOID);
                break;
            default:
                /* Complain if it's not a valid optional proc number */
                if (procform->amprocnum < BRIN_FIRST_OPTIONAL_PROCNUM ||
                    procform->amprocnum > BRIN_LAST_OPTIONAL_PROCNUM)
                {
                    ereport(INFO,
                            (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                             errmsg("operator family \"%s\" of access method %s contains function %s with invalid support number %d",
                                    opfamilyname, "brin",
                                    format_procedure(procform->amproc),
                                    procform->amprocnum)));
                    result = false;
                    continue;    /* omit bad proc numbers from allfuncs */
                }
                /* Can't check signatures of optional procs, so assume OK */
                ok = true;
                break;
        }

        if (!ok)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains function %s with wrong signature for support number %d",
                            opfamilyname, "brin",
                            format_procedure(procform->amproc),
                            procform->amprocnum)));
            result = false;
        }

        /* Track all valid procedure numbers seen in opfamily */
        allfuncs |= ((uint64) 1) << procform->amprocnum;
    }

    /* Check individual operators */
    for (i = 0; i < oprlist->n_members; i++)
    {
        HeapTuple    oprtup = &oprlist->members[i]->tuple;
        Form_pg_amop oprform = (Form_pg_amop) GETSTRUCT(oprtup);

        /* Check that only allowed strategy numbers exist */
        if (oprform->amopstrategy < 1 || oprform->amopstrategy > 63)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with invalid strategy number %d",
                            opfamilyname, "brin",
                            format_operator(oprform->amopopr),
                            oprform->amopstrategy)));
            result = false;
        }
        else
        {
            /*
             * The set of operators supplied varies across BRIN opfamilies.
             * Our plan is to identify all operator strategy numbers used in
             * the opfamily and then complain about datatype combinations that
             * are missing any operator(s).  However, consider only numbers
             * that appear in some non-cross-type case, since cross-type
             * operators may have unique strategies.  (This is not a great
             * heuristic, in particular an erroneous number used in a
             * cross-type operator will not get noticed; but the core BRIN
             * opfamilies are messy enough to make it necessary.)
             */
            if (oprform->amoplefttype == oprform->amoprighttype)
                allops |= ((uint64) 1) << oprform->amopstrategy;
        }

        /* brin doesn't support ORDER BY operators */
        if (oprform->amoppurpose != AMOP_SEARCH ||
            OidIsValid(oprform->amopsortfamily))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains invalid ORDER BY specification for operator %s",
                            opfamilyname, "brin",
                            format_operator(oprform->amopopr))));
            result = false;
        }

        /* Check operator signature --- same for all brin strategies */
        if (!check_amop_signature(oprform->amopopr, BOOLOID,
                                  oprform->amoplefttype,
                                  oprform->amoprighttype))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with wrong signature",
                            opfamilyname, "brin",
                            format_operator(oprform->amopopr))));
            result = false;
        }
    }

    /* Now check for inconsistent groups of operators/functions */
    grouplist = identify_opfamily_groups(oprlist, proclist);
    opclassgroup = NULL;
    foreach(lc, grouplist)
    {
        OpFamilyOpFuncGroup *thisgroup = (OpFamilyOpFuncGroup *) lfirst(lc);

        /* Remember the group exactly matching the test opclass */
        if (thisgroup->lefttype == opcintype &&
            thisgroup->righttype == opcintype)
            opclassgroup = thisgroup;

        /*
         * Some BRIN opfamilies expect cross-type support functions to exist,
         * and some don't.  We don't know exactly which are which, so if we
         * find a cross-type operator for which there are no support functions
         * at all, let it pass.  (Don't expect that all operators exist for
         * such cross-type cases, either.)
         */
        if (thisgroup->functionset == 0 &&
            thisgroup->lefttype != thisgroup->righttype)
            continue;

        /*
         * Else complain if there seems to be an incomplete set of either
         * operators or support functions for this datatype pair.
         */
        if (thisgroup->operatorset != allops)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s is missing operator(s) for types %s and %s",
                            opfamilyname, "brin",
                            format_type_be(thisgroup->lefttype),
                            format_type_be(thisgroup->righttype))));
            result = false;
        }
        if (thisgroup->functionset != allfuncs)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s is missing support function(s) for types %s and %s",
                            opfamilyname, "brin",
                            format_type_be(thisgroup->lefttype),
                            format_type_be(thisgroup->righttype))));
            result = false;
        }
    }

    /* Check that the originally-named opclass is complete */
    if (!opclassgroup || opclassgroup->operatorset != allops)
    {
        ereport(INFO,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("operator class \"%s\" of access method %s is missing operator(s)",
                        opclassname, "brin")));
        result = false;
    }
    for (i = 1; i <= BRIN_MANDATORY_NPROCS; i++)
    {
        if (opclassgroup &&
            (opclassgroup->functionset & (((int64) 1) << i)) != 0)
            continue;            /* got it */
        ereport(INFO,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("operator class \"%s\" of access method %s is missing support function %d",
                        opclassname, "brin", i)));
        result = false;
    }

    ReleaseCatCacheList(proclist);
    ReleaseCatCacheList(oprlist);
    ReleaseSysCache(familytup);
    ReleaseSysCache(classtup);

    return result;
}
